JP4296062B2 - Method for manufacturing pattern forming mold - Google Patents

Description

  The present invention relates to a method for producing a pattern molding die, and can be used for, for example, a photolithography process in a LIGA process. Particularly, a molding die having a high aspect pattern (referring to a pattern having a high aspect ratio) can be accurately and easily used. The present invention relates to a method for manufacturing a pattern molding die that can be suitably used as a technology that can be manufactured easily.

  Attempts have been made to use the LIGA process as a technology for manufacturing fine components. The LIGA process enables the mass production of fine parts by forming a resist pattern similar to the desired part in the lithography process, creating a metal pattern in the electroforming process, and then performing a resin molding process using the metal pattern. Technology. The LIGA process is described in detail in Chapter 1 of “LIGA Process” (Nikkan Kogyo Shimbun), and the elemental technology of the process is described in detail in Chapter 2 of the book. In the lithography process of this LIGA process, active energy rays in the lithography process are generally radiated due to the limitation of processing a very thick resist film having a thickness exceeding 50 μm, and more than 100 μm and performing high aspect processing. X-rays obtained from light or the like are used.

  X-rays obtained from this radiated light are used because they have high transparency to resist materials and high linearity, so that high aspect patterns can be easily obtained. In general, PMMA (polymethyl methacrylate) is used as the resist material. On the other hand, an attempt to apply a negative resist called SU-8 (trade name), which is a resist material, to the LIGA process has also been reported (see Patent Document 1). SU-8 is a photocationic polymerization-based curing composition comprising an epoxy resin and a radiation-sensitive cationic polymerization initiator, but has less curing shrinkage that occurs during the reaction than a photoradical polymerization-based curing composition using acrylate or the like. Is known and is suitable for processing very thick films as in the LIGA process.

  However, since the PMMA coating method polymerizes methyl methacrylate monomer on the substrate by a polymerization reaction, the film thickness accuracy is poor and accompanied by a very complicated process (see Non-Patent Document 1, etc.). Further, in order to process PMMA having a large film thickness, radiant light that can obtain X-rays with very strong intensity is used, but the processing time is very long and is not practical. Furthermore, PMMA has a problem that it is not sensitive to a high-pressure mercury lamp which is a highly versatile light source. Although synchrotron radiation has the advantage of very high pattern accuracy, it requires a large amount of equipment and is disadvantageous as a light source.

  SU-8 (trade name) shows very good sensitivity and patternability for high-pressure mercury lamps, but has an aromatic ring in the skeleton of the novolac type epoxy resin used in the material, and therefore has a wavelength of 300 nm or less. There is a problem that exposure is limited due to strong absorption in the UV region. Since semiconductor microfabrication in recent years has proved that shortening the exposure wavelength is effective for improving the pattern accuracy in the UV region, the inability to use the Deep UV region is a disadvantage. Furthermore, it is necessary to select a cationic initiator that matches the absorption (transparency) of the resin, but since many of the cationic initiators on the market match the absorption range of the novolak epoxy resin, the matching initiator is There is also a problem that the range of selection is small.

  On the other hand, as an aliphatic epoxy resin having no aromatic ring, for example, glycidyl (meth) acrylate, CYCLOMER A200, CYCLOMER M100 [both A200 and M100 are manufactured by Daicel Chemical Industries, Ltd .; Acrylate] and Celoxide 2000 (1-vinyl-3,4-epoxycyclohexane manufactured by Daicel Chemical Industries, Ltd.) are marketed as monomers, and epoxy resins can be synthesized from these monomers by a method such as radical polymerization.

  However, in the case of (meth) acrylates such as glycidyl (meth) acrylate, CYCLOMER A200, and CYCLOMER M100, the (meth) acrylate skeleton of the main chain skeleton has high energy activity such as electron beam, deep UV, and X-ray. It is known that the wire has a relatively high sensitivity, and in this case, side reactions other than the polymerization reaction due to the desired epoxy group occur in the main chain part that has the greatest influence on the physical properties, so that the patterning property, exposure sensitivity, and curing It is not preferable because the physical properties vary or adversely affect. In addition, Celoxide 2000 having no (meth) acrylic skeleton is concerned about its toxicity and has a problem that strict management is required for use.

Japanese Patent Publication No. 7-78628 J. Mohr, W. Ehrfeld and D. Meunchmeryer: J. Vac. Sci. Technol., B6, 2264 (1988)

  In view of such circumstances, the present invention can apply a resist composition by a simple method such as spin coating with high film thickness accuracy and film thickness controllability, has a large pattern accuracy and a wide selection range of exposure light source, and exposure. It is an object of the present invention to provide a pattern forming mold manufacturing method for manufacturing a pattern forming mold made of metal and resin from a high aspect pattern with a short time, high productivity, and high pattern accuracy.

  As a result of repeating various studies to solve the above problems, the present inventor uses a specific aliphatic epoxy resin having no (meth) acrylic skeleton, particularly in combination with a predetermined initiator, for pattern formation. The resist composition can be applied by a simple method such as spin coating with high film thickness accuracy and film thickness controllability, the desired pattern accuracy and exposure light source selection range is large, the exposure time is short, and the productivity is high. The inventors have found that a pattern forming mold such as metal and resin can be produced from a high-accuracy high aspect pattern, thereby completing the present invention.

The first aspect of the present invention is based on a radiation-sensitive negative resist composition comprising an epoxy resin represented by the general formula (1), a radiation-sensitive cationic polymerization initiator, and a solvent for dissolving the epoxy resin. A first step of applying the radiation-sensitive negative resist composition, a second step of obtaining a resist film by drying the substrate coated with the radiation-sensitive negative resist composition, and a desired pattern of the obtained resist film by active energy rays A third step of selectively exposing in accordance with the above, a fourth step of improving the contrast by heat-treating the resist film after the exposure, and developing the resist film after the heat treatment to form a resist material in an unexposed area A fifth step of obtaining a pattern layer by dissolution and removal, and forming a second pattern layer by providing another material at least in the concave portion of the pattern layer, and separating the second pattern layer Have a a sixth step of a for emissions mold, at least one anion of the radiation-sensitive cationic polymerization initiator, characterized in that it is a borate compound represented by the following formula (6) It exists in the manufacturing method of the pattern shaping die.

(In the formula, R ¹ is an organic compound residue having k active hydrogens (k is an integer of 1 to 100), n ₁ , n ₂ ... _Nk is 0 or an integer of 1 to 100. The sum is 1 to 100, and A is the same or different oxycyclohexane skeleton represented by the following formula (2).

  (In the formula, X represents any of the following formulas (3) to (5), but contains at least two formulas (3) in one molecule.)

(In the formula, R ² is a hydrogen atom, an alkyl group, or an acyl group. The alkyl group and the acyl group preferably have 1 to 20 carbon atoms.)

(Wherein x _{1 to} x ₄ represent an integer of 0 to 5, and the sum of x ₁ + x ₂ + x ₃ + x ₄ is 1 or more.)

According to a second aspect of the present invention, there is provided the method for producing a pattern molding die according to the first aspect, wherein the resist film has a thickness of 50 μm or more.

  In the present invention, a pattern forming die can be manufactured from a high aspect pattern which is highly productive and simple and can be formed using various light sources. The pattern molding die obtained by the production method of the present invention can be used as a “mold” for molding other parts having the same pattern as the resist pattern. Further, the pattern forming die itself obtained by the production method of the present invention can be used as a component such as a micromachine or a microchip.

  The present invention is formed using a variety of light sources that are highly productive and simple by selecting an epoxy resin represented by the general formula (1) from a number of conventional curable resin compositions. A resist pattern having a high aspect ratio that can be obtained is obtained, and the pattern forming mold can be suitably produced using the resist pattern. Such an epoxy resin is disclosed in Japanese Patent Application Laid-Open No. 60-166675, and a curable resin composition mainly composed of this epoxy resin and a photoinitiator is disclosed in Japanese Patent Application Laid-Open No. 61-283614. Although it is disclosed in the official gazette, it was originally developed as a simple UV curable resin composition, and no pattern formation is mentioned. Of course, as in the present invention, a pattern molding die made of metal or the like is used. There is no description that suggests a manufacturing method of a pattern forming die for forming a thick film pattern, such as the LIGA process, so that the productivity is high and it can be easily formed using various light sources. It is not easily expected that an effect that a pattern forming mold can be suitably produced from a resist pattern having an aspect ratio will be obtained.

  The method for producing a pattern molding die of the present invention comprises a radiation-sensitive negative resist composition comprising an epoxy resin represented by the general formula (1), a radiation-sensitive cationic polymerization initiator, and a solvent for dissolving the epoxy resin. The first step of applying to the substrate, the second step of obtaining a resist film by drying the substrate coated with this radiation-sensitive negative resist composition, and the desired resist film by active energy rays A third step of selectively exposing in accordance with the pattern, a fourth step of improving the contrast by heat-treating the exposed resist film, and developing the resist film after the heat treatment to develop a resist in an unexposed area. A fifth step of obtaining a pattern layer by dissolving and removing the material, and forming a second pattern layer by providing another material at least in the concave portion of the pattern layer, and separating the second pattern layer And having a sixth step of the pattern mold with.

  The radiation-sensitive negative resist composition applied to the substrate in the first step comprises an epoxy resin represented by the general formula (1), a radiation-sensitive cationic polymerization initiator, and a solvent for dissolving the epoxy resin. Including. When such a radiation-sensitive negative resist is used, it can be applied by a simple method such as spin coating with high film thickness accuracy and high film thickness controllability. The softening point of the resist film obtained after drying the radiation-sensitive negative resist composition is not particularly limited, but is preferably in the range of 30 to 120 ° C, more preferably 35 to 100 ° C, and more preferably 40 to 80. Use the one in the range of ° C. The softening point here is defined for a resist film obtained after predetermined drying. The resist film obtained after predetermined drying is a method in which a radiation-sensitive negative resist composition is applied to a substrate and dried. It refers to a resist film obtained such that the amount of solvent remaining in the coating film is 10% by weight or less. The resist film obtained after drying continuously changes from a solid state with a high viscosity to a fluid state with a low viscosity when heated, but the temperature at which a specific viscosity is exhibited in this softening process is The softening point of the resulting resist film, specifically, a measured value obtained using the method of JIS K 7234.

  The softening point of the resist film obtained after drying the radiation-sensitive negative resist composition thus measured is mainly the type and content of the epoxy resin and the radiation-sensitive cationic polymerization initiator, as well as the solvent remaining during drying, In addition, it depends on the type and amount of additives, and the softening point can be adjusted by changing them. Although the softening point of the resist film obtained after drying so that the amount of the solvent remaining in the resist coating is 10% by weight or less is preferably in the range of 30 to 120 ° C., the radiation-sensitive negative resist It does not prescribe the dry state when the composition is used. Therefore, even when a composition having a softening point in the above-described range is used, it may be used in the second step such that the amount of the solvent remaining after the drying step exceeds 10% by weight.

  Such a negative resist composition can be used for thick film processing exceeding 50 μm. However, in the thick film processing, the difference from the resist used for forming a known thin film is that The point which the removal of the stress which the volume reduction accompanying distillation of requires requires is mentioned. This is because when the film is thick, the influence of stress becomes particularly significant, and defects such as wrinkles, cracks, and bubbles are likely to occur in the resist film. When the negative resist composition having the softening point of the resist film obtained after drying in the above temperature range as described above, the stress is relieved by the softening of the resist film during the drying process, and wrinkles of the resist film are generated. In addition, tack does not occur at room temperature.

The polyether-type epoxy resin represented by the general formula (1) is, for example, a polyether compound vinyl obtained by reacting an organic compound having active hydrogen with 4-vinylcyclohexene-1-oxide in the presence of a catalyst. It can be obtained by partially or fully epoxidizing the group with an oxidizing agent such as peracids such as peracetic acid or hydroperoxides. At this time, a small amount of acyl group or the like may be introduced. Examples of the organic compound having active hydrogen include alcohols such as linear or branched aliphatic alcohols, preferably polyhydric alcohols such as trimethylolpropane, phenols, carboxylic acids, amines, thiols, and the like. Is mentioned. These organic compounds having active hydrogen are preferably those having a molecular weight of 10,000 or less. In addition, the residue from which active hydrogen is eliminated from the organic compound having active hydrogen is R ^{1 in the} formula (1). Moreover, it can also obtain easily from a market, for example, Daicel Chemical Industries Ltd. make, EHPE-3150 (epoxy equivalent 170-190, softening point 70-90 degreeC) etc. are mentioned.

  The softening point of the epoxy resin represented by the general formula (1) is not particularly limited. However, if it is too low, the resist film after drying tends to cause tackiness, and is preferably 30 ° C. or higher, more preferably 40. ~ 140 ° C.

  The radiation-sensitive cationic polymerization initiator contained in the radiation-sensitive negative resist composition can be used without particular limitation as long as it generates an acid upon irradiation with a known active energy ray. For example, a sulfonium salt , Iodonium salts, phosphonium salts, pyridinium salts, and the like.

  Examples of the sulfonium salt include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, bis (4- (diphenylsulfonio) -phenyl) sulfide-bis (hexafluorophosphate), bis (4- (diphenylsulfo). Nio) -phenyl) sulfide-bis (hexafluoroantimonate), 4-di (p-toluyl) sulfonio-4'-tert-butylphenylcarbonyl-diphenylsulfide hexafluoroantimonate, 7-di (p-toluyl) sulfonio 2-isopropylthioxanthone hexafluorophosphate, 7-di (p-toluyl) sulfonio-2-isopropylthioxanthone hexafluoroantimonate and the like, and JP-A-7-61964 Distribution, JP 8-165290, JP No. 4231951, and aromatic sulfonium salts described in U.S. Patent No. 4,256,828 and the like.

  Examples of the iodonium salt include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, JP-A-6-184170, US Pat. No. 4,256,828, and the like. And aromatic iodonium salts described in the above.

  Examples of the phosphonium salt include tetrafluorophosphonium hexafluorophosphate, tetrafluorophosphonium hexafluoroantimonate, and aromatic phosphonium salts described in JP-A-6-157624.

  Examples of the pyridinium salt include pyridinium salts described in Japanese Patent No. 2519480, Japanese Patent Laid-Open No. 5-222112, and the like.

  The negative resist composition can be used for thick film processing exceeding 50 μm. In such thick film processing, as a difference from a known epoxy-containing resist used for forming a thin film, a resist solution For example, the drying time in the drying process after coating is long and the developing time in the developing process is long. Therefore, in order to make the negative resist composition thick, high thermal stability and high contrast between the exposed area and the unexposed area are required. Therefore, among the radiation-sensitive cationic polymerization initiators described above, sulfonium is used. When salts are used, the thermal stability of the negative resist composition is increased, so that the radiation-sensitive cationic polymerization initiator is preferably one or more sulfonium salts.

In addition, it is preferable that at least one of the anions of the radiation-sensitive cationic polymerization initiator is SbF ₆ ⁻ or borates represented by the following formula (6), since the contrast of the negative resist composition is increased. More preferred examples of the borates include tetrakis (pentafluorophenyl) borate.

(Wherein x _{1 to} x ₄ represent an integer of 0 to 5, and the sum of x ₁ + x ₂ + x ₃ + x ₄ is 1 or more.)

  The sulfonium salt and the iodonium salt can be easily obtained from the market. Examples of radiation-sensitive cationic polymerization initiators that can be easily obtained from the market include UVI-6990 and UVI-6974 manufactured by Union Carbide, Adeka Optomer SP-170 and Adeka manufactured by Asahi Denka Kogyo Co., Ltd. Examples include sulfonium salts such as optomer SP-172 and iodonium salts such as PI 2074 manufactured by Rhodia.

  The addition amount of these radiation-sensitive cationic polymerization initiators is not particularly limited, but is preferably 0.1 to 15 parts by weight, more preferably 1 to 12 parts by weight with respect to 100 parts by weight of the epoxy resin.

  The solvent for dissolving the epoxy resin contained in the radiation-sensitive negative resist composition is not particularly limited as long as it is a solvent that dissolves the epoxy resin. For example, propylene such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate Glycol monoalkyl ether acetates, lactate alkyl esters such as methyl lactate and ethyl lactate, propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. Ethylene glycol monoalkyl ethers, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether Ethylene glycol monoalkyl ether acetates such as cetate, 2-heptanone, gamma-butyrolactone, alkyl alkoxypropionates such as methyl methoxypropionate and ethyl ethoxypropionate, and pyruvate alkyl esters such as methyl pyruvate and ethyl pyruvate And ketones such as methyl ethyl ketone, cyclopentanone and cyclohexanone, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, propylene carbonate, diacetone alcohol and the like. These solvents can be used alone or in combination. Of the above solvents, γ-butyrolactone is particularly preferred.

  The radiation-sensitive negative resist composition containing each of the above components preferably contains 10 to 90% by weight, more preferably 40 to 85% by weight, of the solid content in the solvent for dissolving the epoxy resin. More preferably, it is 60 to 80% by weight. This is because if the solid content concentration is too low, it is difficult to apply with a sufficient film thickness, and if the solid content concentration is too high, the viscosity increases and application becomes difficult.

  In addition, various additives such as surfactants, acid diffusion inhibitors, pigments, dyes, sensitizers, and plasticizers can be added to the radiation-sensitive negative resist composition as necessary.

  There are no particular restrictions on the support substrate on which the negative resist composition is applied and its surface. Examples of the substrate include silicon, glass, metal, ceramic, and organic polymer. These base materials can also be subjected to pretreatment of the base material for the purpose of improving adhesiveness, and for example, improvement of adhesiveness can be expected by performing silane treatment. Further, when obtaining a metal pattern molding die, the plating process can be easily performed if the surface of the substrate is made conductive.

  The process for applying the radiation-sensitive negative resist composition to the substrate is not particularly limited, but application methods such as screen printing, curtain coating, blade coating, spin coating, spray coating, dip coating, and slit coating can be applied. .

  The substrate coated with the radiation-sensitive negative resist composition in the first step is dried in the second step to obtain a resist film. Although there is no particular limitation on the drying process, it is preferable to perform the drying process at a temperature and a time at which the solvent contained in the negative resist composition is volatilized and a tack-free resist film can be formed. In addition, it is preferable that the epoxy resin, the radiation-sensitive cationic polymerization initiator, and other additives added as necessary cause the temperature and time so as not to cause a thermal reaction and cause problems in pattern formation. Therefore, the drying conditions are preferably 40 to 120 ° C. and 5 minutes to 24 hours, for example. The film thickness of the resist film is not particularly limited. For example, even a thick film of 50 μm or more can be processed with high accuracy in the subsequent steps, but it is particularly preferably 50 μm to 2 mm.

  In the third step, the resist film obtained in the second step is selectively exposed in accordance with a desired pattern using active energy rays. The active energy ray used for exposure is not particularly limited. Examples of the active energy rays include ultraviolet rays, excimer lasers, electron beams, and X-rays. However, using X-rays having a wavelength of 0.1 to 5 nm is particularly preferable because pattern accuracy is improved. In the production method of the present invention, since the radiation-sensitive negative resist composition as described above is used, for example, even if the resist film is a thick film of 50 μm or more, the exposure time in this exposure step is short, and the active energy The line can be selected according to the desired pattern accuracy, and, for example, highly versatile ultraviolet light (light source: high-pressure mercury lamp, etc.) can be used.

  The resist film exposed in the third step is improved in contrast by heat in the fourth step. If this step is omitted, the reaction of the epoxy resin is not sufficient, and a highly accurate pattern cannot be obtained. In the fourth step, it is necessary to perform heat treatment at a temperature and a time in a range in which the unexposed portion of the resist undergoes a thermal reaction and does not become insoluble in the developer. A preferred temperature is 70 to 110 ° C, more preferably 80 to 100 ° C, and a preferred time is 5 minutes to 10 hours. This is because if the temperature is lower than the above range or if the time is too short, the contrast becomes insufficient, and if the temperature is too high or too long, problems such as unexposed portions becoming insoluble in the developer occur.

  The resist film heat-treated in the fourth step is developed in the fifth step, and the resist material in the unexposed areas is dissolved and removed to obtain a pattern layer. In the present invention, since the resist film is thick, high in strength, and excellent in resolution, a pattern layer having a high aspect pattern can be formed. For example, a pattern having an aspect ratio of 10 or more may be formed. it can.

  The developer is not particularly limited as long as it is a solvent that dissolves and removes the negative resist in the unexposed areas, but propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, methyl lactate, Lactic acid alkyl esters such as ethyl lactate, propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ethylene glycol monomethyl Ethylene glycol monoalkyl ethers such as ether acetate and ethylene glycol monoethyl ether acetate Cetates, 2-heptanone, γ-butyrolactone, alkyl methoxypropionates, alkyl alkoxypropionates such as ethyl ethoxypropionate, pyruvate alkyl esters such as methyl pyruvate, ethyl pyruvate, methyl ethyl ketone, cyclopentanone, cyclohexanone And ketones such as N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, propylene carbonate and diacetone alcohol, and γ-butyrolactone, propylene glycol monomethyl ether acetate and the like are particularly preferable.

  The developing method can be any of a spray method, a paddle method, a dipping method, and the like, but the dipping method is preferable because there is little pattern destruction such as peeling of the pattern. Moreover, an ultrasonic wave etc. can also be irradiated as needed.

  In the fifth step, it is preferable to carry out a rinsing step as necessary after development. However, the rinsing step, the rinsing liquid and the rinsing method are not particularly limited, and can be carried out using known solutions and methods.

  Further, after the development or rinsing step, the pattern can be stabilized by heating the resist pattern under known conditions.

  By providing a second pattern layer by providing another material in at least the concave portion of the pattern layer obtained in the fifth step, and separating the second pattern layer to obtain a pattern molding die. A pattern molding die is obtained. That is, for example, as shown in FIGS. 1 and 2, the second pattern is made of another material in at least the concave portion of the pattern layer 2 (FIGS. 1A and 2A) formed on the substrate 1. By providing the layer 3, a composite structure of the pattern layer 2 and the second pattern layer 3 can be obtained (FIGS. 1B and 2B). In addition, the 2nd pattern layer 3 may be provided only in the recessed part of the pattern layer 2, and may be provided in the whole surface so that the pattern layer 2 may be covered. When the second pattern layer 3 is separated from the composite structure of the pattern layer 2 and the second pattern layer 3, the pattern forming die 4 to which the resist pattern of the pattern layer 2 has been transferred is obtained (FIG. 1C). FIG. 2 (c)). The pattern molding die 4 can be used as a “mold” for molding other parts, but can also be used as a part as it is.

  As described above, since a resist pattern layer having a high aspect pattern can be formed in the present invention, a pattern molding die to which this high aspect pattern is transferred can be manufactured. For example, the aspect ratio is 10 or more. It can also be.

  The material for forming the second pattern layer 3 is not particularly limited, but when the material is a metal, for example, a metal pattern forming mold can be obtained by providing it by a plating process.

  The method of the plating process is not particularly limited, but the electrolytic plating method is preferable. As a method of performing metal plating such as copper, nickel, silver, gold, solder, a multilayer of copper / nickel, or a composite system thereof, a conventionally known method can be used. For example, “Surface treatment technology overview” ( Technical Data Center Co., Ltd., 1987/12/21 first edition, p. 281-422.

  The process of separating the second pattern layer 3 provided by the plating process from the composite structure of the pattern layer 2 and the second pattern layer 3 is not particularly limited, but a known wet method or dry method can be used. For example, in the wet method, a method such as immersion in a chemical such as an organic solvent such as N-methylpyrrolidone or an organic alkaline solution such as ethanolamine, etc., and in the dry method, a dry etching method such as reactive ion etching or an ashing treatment can be mentioned. It is done.

  The material for forming the second pattern layer 3 may be a resin. In this case, for example, the second pattern layer 3 is provided by casting light or thermosetting resin, and the resin is cured by light or heat. Then, a resin pattern molding die can be obtained.

  The process of separating the second pattern layer 3 made of light or thermosetting resin from the composite structure of the pattern layer 2 and the second pattern layer 3 is not particularly limited, but can be physically peeled off, for example. In addition, when the second pattern layer 3 has sufficient resistance to the wet method or the dry method described above, these methods can also be used. The light or thermosetting resin is not particularly limited. For example, when light or thermosetting PDMS (polydimethylsiloxane) is used, the pattern can be transferred by being easily cured by light or heat. The separation is particularly preferable because it can be easily physically peeled off.

  As described above, according to the present invention, the resist composition can be applied by a simple method such as spin coating and with high film thickness accuracy and film thickness controllability, and the desired pattern accuracy and the range of selection of the exposure light source are large. A pattern molding die made of a metal, a resin, or the like can be manufactured from a resist pattern having a high aspect ratio with a short exposure time, high productivity, and high pattern accuracy.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

  1. Preparation of radiation-sensitive negative resist composition for pattern formation

(Example 1 and Reference Examples 1 to 3 )
Resist materials were mixed at a ratio shown in Table 1 to obtain a uniform composition using a three-roll mill to prepare a radiation-sensitive negative resist composition for pattern formation. The structural formulas and trade names of the epoxy resin and the cationic polymerization initiator are shown in the following [Chemical 8] and [Chemical 9].

Resin-1: EHPE-3150 (Brand name: Daicel Chemical Industries epoxy resin)
Resin-2: EPON SU-8 (Brand name: Epoxy resin made by Shell Chemical)

PI-1: UVI-6974 (trade name: manufactured by Union Carbide, cation initiator, active ingredient 50 wt%, a mixture containing the above compound as a main component)
PI-2: UVI-6990 (trade name: manufactured by Union Carbide, cation initiator, active ingredient 50 wt%, a mixture containing the above compound as a main component)
PI-3: SarCat CD-1012 (Brand name: Sartomer Cationic Initiator)
PI-4: A mixture based on the above compounds

(Comparative Example 1)
In the same manner as in Example 1 and Reference Examples 1 to 3 , a radiation-sensitive negative resist composition for pattern formation having the composition shown in Table 1 was prepared.

  2. Patterning evaluation

(1) Preparation of resist film (Example 1a and Reference Examples 1a to 3a )
After applying the pattern-forming radiation-sensitive negative resist composition of Example 1 and Reference Examples 1 to 3 on a silicon substrate that had been surface-treated with copper by a sputtering method, on a hot plate at 90 ° C. It was dried for 30 minutes to obtain a 100 μm thick resist film.

(Comparative Example 1a)
With reference to Examples 1 and patterning radiation-sensitive negative resist composition of Comparative Example 1 in place of the pattern forming radiation-sensitive negative resist composition of Reference Example 1-3, Example 1a and Example 1a~3a In the same manner as described above, a 100 μm resist film was obtained.

(Comparative Example 2a)
PMMA syrup (Rohm PMMA (polymethyl methacrylate), thermal polymerization initiator, crosslinker MMA (methyl methacrylate) solution) was cast on a silicon substrate. At that time, the glass slide was used as a gap, pressed by a glass plate, and polymerized and cured at 110 ° C. for 1 hour. Thereafter, cooling was performed at a rate of 15 ° C./hour to obtain a 100 μm PMMA resist film.

(Test Example 1)
In order to evaluate the uniformity (applicability) of the resist films obtained in Example 1a, Reference Examples 1a to 3a , and Comparative Examples 1a and 2a, film thicknesses at three arbitrary points on the substrate were measured. The applicability was evaluated with “「 ”when the difference between the maximum value and the minimum value of the measured values was less than 5 μm,“ ◯ ”when the difference was 5 to 10 μm, and“ X ”when the difference was more than 10 μm. The results are shown in Table 2.

(2) Formation of resist pattern (Example 1b and Reference Examples 1b to 3b )
When a high-pressure mercury lamp is used as the light source or when a KrF excimer laser is used, when a quartz UV mask is used as a mask and synchrotron X-rays (wavelength: 0.2 to 1 nm) are used, the diamond membrane The resist film of Example 1a and Reference Examples 1a to 3a was irradiated with an X-ray mask having a gold absorber pattern formed thereon , followed by heat treatment on a hot plate at 90 ° C. for 10 minutes, and then propylene glycol Development was performed by immersing in monomethyl ether acetate for 30 minutes to obtain a resist pattern. The exposure amount is shown in Table 2.

(Comparative Example 1b)
Resist patterns were obtained in the same manner as Example 1b and Reference Examples 1b to 3b , using the resist film of Comparative Example 1a instead of the resist films of Example 1a and Reference Examples 1a to 3a .

(Comparative Example 2b)
After irradiating the PMMA resist film of Comparative Example 2a using a mask in the same manner as Example 1b and Reference Examples 1b to 3b, it was immersed in a mixture of ethanol, oxazine, aminoethanol, and water for 12 hours while being subjected to ultrasonic waves. Development was performed to obtain a resist pattern.

(Test Example 2)
The resist patterns obtained in Example 1b, Reference Examples 1b to 3b, and Comparative Examples 1b and 2b were observed with an optical microscope. When there was no pattern meandering due to swelling, “◎”, wrinkles were observed on the top of the pattern due to swelling. However, when the pattern meandering was not observed, “◯” was indicated, and when the pattern meandering was indicated as “X”, the sensitivity was evaluated.

  In addition, when the resist pattern is a pattern having a mask line width of 10 μm (aspect ratio 10), “」 ”, and when a pattern having a mask line width of 20 μm is resolved (aspect ratio 5),“ ◯ ”is resolved. The resolution was evaluated as “x” when not. The results are shown in Table 2.

Reference Example 1a and Example 1a have good coating properties, and Reference Example 1b and Example 1b showed good results under all exposure conditions of X-rays using a high-pressure mercury lamp, KrF excimer laser, and synchrotron light.

Reference Example 2a had good coating properties, and Reference Example 2b showed generally good results although it was slightly inferior in curing sensitivity to Reference Example 1b.

In Reference Example 3a, the coating property was good, and in Reference Example 3b, the developing speed of the unexposed portion was slow, and some adverse effects were observed on the pattern properties, but the results were generally good.

  Comparative Example 1a had good coating properties, and Comparative Example 1b showed good results when exposed to X-rays using a high-pressure mercury lamp and synchrotron light, but pattern formation was not possible when exposed to KrF excimer laser.

In Comparative Example 2a, a resist film having a uniform film thickness cannot be obtained, and in Comparative Example 2b, a pattern cannot be formed unless the exposure conditions are increased to 10000 J / cm ² with synchrotron light to a practically difficult exposure amount. confirmed.

  3. Softening point measurement and appearance test of resist film obtained after drying

(Test Example 3)
For the resist film of Reference Example 1a, measurement according to the method of JIS K 7234 and visual observation of the film state were performed. As a result, the softening point was 60 ° C., and it was a good resist film free from tack and wrinkles.

  4). Formation of metal pattern mold

( Reference Example 1c)
The substrate on which the resist pattern of Reference Example 1b is formed is dipped in microfab Au100 (trade name: Tanaka Kikinzoku plating solution), and energized at a current value of 1 to 10 A / 100 cm ² at room temperature to form an Au plating layer (second pattern layer). ) Was formed. This was immersed in an aqueous solution adjusted to a concentration of 250 g / L of chromium oxide (VI) and 15 mL / L of sulfuric acid and separated from the substrate by etching the copper on the substrate, and then N-methylpyrrolidone at 120 ° C. The resist pattern was removed by immersing in the solution for 2 hours to obtain a metal (Au) pattern molding die.

(Comparative Example 2c)
It carried out similarly to the reference example 1c except having used the board | substrate in which the resist pattern of the comparative example 2b was formed instead of the reference example 1b.

(Test Example 4)
The metal pattern forming molds obtained in Reference Example 1c and Comparative Example 2c were observed with a microscope, and the reverse pattern shape in which the plating was performed uniformly and the resist pattern before plating was transferred was accurately performed. The case where it was formed was evaluated as “◯”, and the case where plating was not performed uniformly and / or there was a portion where the reverse pattern shape to which the resist pattern was transferred was not obtained was evaluated as “x”. The results are shown in Table 3.

  5). Formation of resin pattern molding die

( Reference Example 1d)
Unpolymerized PDMS (Dow Corning, Sylgard 184) mixed at a ratio of main agent: polymerizing agent = 10: 1 was poured onto the substrate on which the resist pattern of Reference Example 1b was formed, and the mixture was heated and polymerized at 100 ° C. for 2 hours. The substrate was cooled to room temperature, and the cured PDMS was physically peeled from the substrate to obtain a pattern forming mold made of resin (PDMS).

(Comparative Example 2d)
The same procedure as in Reference Example 1d was performed except that the substrate on which the resist pattern of Comparative Example 2b was formed instead of Reference Example 1b was used.

(Test Example 5)
The resin pattern molding molds obtained in Reference Example 1d and Comparative Example 2d were observed with a microscope, and the resist pattern was not damaged in the PDMS pattern, and the reverse pattern shape to which the resist pattern was transferred was accurate. The case where it was formed was evaluated as “◯”, and the case where there was a damaged material and / or the case where the reverse pattern shape to which the resist pattern was transferred was not obtained was evaluated as “X”. The results are shown in Table 3.

As shown in Table 3, in Reference Examples 1c and 1d, a metal pattern molding die and a resin pattern molding die were successfully formed. In addition, since the favorable resist pattern is obtained also in the other Examples and Reference Examples , a good metal pattern forming mold and resin pattern forming mold are formed as in Reference Examples 1c and 1d. It is estimated that On the other hand, in Comparative Examples 2c and 2d, most of the resist patterns could not be formed as described above, so a metal pattern forming mold or a resin pattern forming mold could not be provided, and the resist pattern was The synchrotron light that can be formed and increased to a practically difficult exposure amount of 10000 J / cm ² , the mechanical strength of the resist pattern is insufficient and a resin pattern molding die can be provided satisfactorily. There wasn't.

It is a figure which shows the manufacturing method of the pattern shaping die concerning one Embodiment of this invention. It is a figure which shows the manufacturing method of the other mold for pattern shaping | molding concerning one Embodiment of this invention.

Explanation of symbols

1 substrate 2 pattern layer 3 second pattern layer 4 pattern molding die

Claims (2)

A first step of applying a radiation-sensitive negative resist composition comprising an epoxy resin represented by the general formula (1), a radiation-sensitive cationic polymerization initiator, and a solvent for dissolving the epoxy resin to a substrate; A second step of obtaining a resist film by drying the substrate coated with the radiation-sensitive negative resist composition; and a third step of selectively exposing the obtained resist film in accordance with a desired pattern by an active energy ray And a fourth step of improving the contrast by heat-treating the exposed resist film, and a fifth step of developing the heat-treated resist film to dissolve and remove the resist material in the unexposed areas to obtain a pattern layer And a sixth step of forming a second pattern layer by providing another material in at least the concave portion of the pattern layer, and separating the second pattern layer to obtain a pattern molding die. It has at least one anion of the radiation-sensitive cationic polymerization initiator, method of manufacturing a patterned mold, which is a borate compound represented by the following formula (6).
(In the formula, R ¹ is an organic compound residue having k active hydrogens (k is an integer of 1 to 100), n ₁ , n ₂ ... _Nk is 0 or an integer of 1 to 100. The sum is 1 to 100, and A is the same or different oxycyclohexane skeleton represented by the following formula (2).
(In the formula, X represents any of the following formulas (3) to (5), but contains at least two formulas (3) in one molecule.)
(In the formula, R ² is a hydrogen atom, an alkyl group, or an acyl group.)
(Wherein x _{1 to} x ₄ represent an integer of 0 to 5, and the sum of x ₁ + x ₂ + x ₃ + x ₄ is 1 or more.) 2. The method for manufacturing a pattern molding die according to claim 1 , wherein the resist film has a thickness of 50 [mu] m or more.